1. Field of the Invention
This invention discloses novel ultraviolet absorbing heterocyclic formamidines useful for protecting materials against the degradative effects of ultraviolet light.
2. Background Art
Various polymers, plastics, resins, cosmetics, dyes, pigments, lacquers, varnishes, textiles, etc., which are subject to photodegradation by UV-radiation, can be protected by incorporating therein suitable UV-light absorbing agents which will absorb the harmful rays and convert them to relatively harmless forms of energy. To be effective, the light absorbing agent must absorb light efficiently in the ultraviolet portion of the sun's rays which reach the earth, i.e., the range of 280 to 400 nanometers. The agent should also be stable to UV-radiation, compatible with and stable in the medium in which it is incorporated, possess little or no color, be non-toxic, thermally stable, and have low volatility.
The prior art does not teach the novel heterocyclic formamidines of this invention nor their use as valuable UV-light absorbing agents.